Combined switch and circuit-breaker.



No. 679,|5|. Patented July 23, IQOI.

T. J. JOHNSTON. COMBINED SWITCH ANO CIRCUIT BREAKER.

(Application filed Feb. 16, 1899.)

(No nodal.)

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THOMAS J. JOHNSTON, OF SCI-IENECTADY, NEYV YORK, ASSIGNOR TO THE GENERAL ELECTRIC COMPANY, OF NEW YORK.

COMBINED SWITCH AND ClRCUlT BREAKER.

SPECIFICATION forming part of Letters Patent No. 679,151, dated July 23, 1901. Application filed February 16, 1899. Serial No. 705,647. (No model.)

To all whom it may concern:

Be it known that I, THOMAS J. JOHNSTON, a citizen of the United States, residing at Schenectady, in the county of Schenectady, State of New York, have invented certain new and useful Improvements in Electric Switches, (Case No. 1,079,) of which the following is a specification.

My present invention relates to electric switches, and has particular reference to the electrically-operated switches which are used in electric-railway systems. It aims to combine with them certain safety arrangements which may be embodied in each switch.

In the installation of surface-contact railways it has been found desirable to assemble the switches in groups in suitable inclosures adjacent to the line of way rather than to bury them beneath the surface and to connect them with the studs or sectional conductor-rails in the road or other suitable lo-. cation by suitable leads. It is highly desirable to prevent undue flow of current in the switches. Their duty is very heavy, and although each switch acts for only a short time it is liable to become overheated if the road is busily operated. To guard against accident to the switches, it is now customary to use an electromagnetic circuit-breaker with each group of switches, a number of different switches being connected in multiple to a common circuit-breaker, so that in case a short circuit or other undue flow of current occurs all in the group will be thrown out of action by the single circuit-breaker. There are a number of objections to this arrangement, one being that it is difficult to' calibrate the circuit-breaker in such a way as to make it safely operate, because, for example, if half a dozen switches be set upon the same circuit-breaker and, as frequently occurs, two or three of them, according to the span of the contact-shoe, should be in operation at once the permitted current in the series coil of the circuit-breaker would be twice or three times that which should flow where only a single switch was in action. Thus a single switch might well be seriously damaged by a heavy current without opening the circuit-breaker.

It is, however, unduly expensive to provide a separate circuit-breaking apparatus for each switch. To obviate these difficulties, I have devised the present invention, which consists of a combined electromagneticallyoperated switch and circuit-breaker. This combination I believe to be new with me. It consists in general of the usual circuit-closing switch, operated by current from a battery or by a shunt from the main circuit, (in ways which are now so well understood in the art as not to require detailed description,) and an auxiliary circuit-opening apparatus by which the circuits of the coils operating the switch are so modified upon excessive currentflow that the switch acts as its own circuitbreaker. It is manifest that the invention here pointed out may find other utilities than those confined to a surface-contact railroad, as under many conditions it is desirable to operate switches electromagnetically. This operation may be and often is performed from a distant point, and it maybe difficult to oversee the action of the switch at all times, yet it may be imperative to prevent undue flow of current. This may be easily accomplished by my invention.

The accompanying drawing shows the in vention applied to a surface-contact-railway system, the switches being shown in section, partly in side elevation, and the circuits and railway apparatus being shown in diagram.

In the drawing, A A are the trackcails.

B is the energizing or pick-up stud of the surface-contact railway.

C is the working stud, which furnishes current to the motors.

It is to be understood that although I have shown the invention with reference to a railway bearing central studs or buttons and long collectors carried by the cars the relative length of the contacts and collectors are immaterial if constant contact is maintained.

It will be observed that the lead from the stud 13 passes through a shunt-energizing coil K upon the switch I and thence to ground, while the lead to the stud C passes from the feeder H to the switch I and through the series coil K of the switch to the stud. Shoes F F,

electrically connected together, register with the studs C B, respectively, and motors M M are connected to the resistance R, which is taken to represent any suitable controlling device between the shoes and the motors. An auxiliary shoe F is also provided, the utility of which will shortly be pointed out. The switch I consists of an iron box I, inclosing a shunt-coil K and a series coil K. A solenoid-core I is actuated by the coils when current is supplied to the switch to draw up the bridge 1 closing the circuit between the feeder and stud O. The cap I of this core stretches the spring I, so that when current is thrown off the core drops and the bridge I opens its contacts. I provide in addition to the parts thus described an armature L,which would not be affected by any ordinary flow of current in the switch and the position of which may be adjusted so as to respond to any desired current-flow. The series coil K has additional contacts M M, which register with contacts M upon the lever L, and these contacts form a short circuit around the series coil. Contacts N N are also provided, through which passes the circuit of the shuntcoil K. A bridging contact N connects these latter contacts N and is carried upon the lever N, with which a spring n cooperates, the lever being normally held in place-as shown, for instance, in the switch on the right of the drawing-by the latch N The operation of the described parts is as follows: The switch upon the left of the drawing is shown as having just actuated its trip, while the switch on the right is in its normal working position. If forany reason an undue flow of current occurs in the coils, the lever L is drawn up (a projection I from the box 1 being provided, so as to shorten the magnetic circuit and increase the range of attraction upon the lever L) and the end of the lever strikes the latch N releasing the lever N 1 and opening the contacts N N. These being in series with the shunt-coil, the latter is at once denergized. The contacts M M are then bridged by the contacts M upon the lever, thus short-circuiting the series coil and permitting the spring I to throw down the bridge 1*. A blow-out magnet-coil is shown diagrammatically at O to rupture any are that might be formed by the opening of the circuit.

It may happen that one or more of the switches may stick and hold alive one of the contacts 0 in the roadway. The arrangement which I have illustrated affords a very c011- venient method of preventing this accident, or rather of neutralizing its ill effect. In line with the shoe F is an auxiliary shoe F electrically connected with the axle of the car and thence to ground. If, therefore, one of the switches I should for any reason stick, the shoeF when it touched the contact 0 would short-circuit the switch to ground, and I before the car would uncover the contact its circuit would be certainly opened, and therefore no conductor section or stud is left alive.

The form of switch which I have shown uses both a shunt and a series coil; but it is manifest that where onlyone coil is used, as in some surface-contact railways or many kinds of electrom agnetically-operated switches, the proper manner of neutralizing the coil would be selected by engineers. For example, if the series coil be employed it would be shortcircuited, while if the shunt-coil be employed it would be open-circuited. It is unnecessary to particularly illustrate and describe such evident modifications; but I aim to include them in the claims.

NVhat I claim as new, and desire to secure by Letters Patent of the United States, is

1. Thecombination,withan electricswitch, normally tending to remain open, of electromagnetic means for closing said switch and holding it closed against such tendency, and a switch which is-actuated by an excessive flow of current through said means to cut the latter out of circuit, so that the switch opens.

2. The combination, with an electricallyoperated switch, of a circuit-breaking device operated by the same coils which actuate the switch.

3. The combination with the switch closed by the passage of current through coils cooperating with a moving part, of means actuated by rise of current in one of the coils for opening the circuit of the switch.

4. The combination with the electricallyopening the switch.

5. The combination with an electromagnetic switch in a surfacecontact-railway sysi tem, of coils closing the contacts of the switch, 1 and an armature actuated by undue current in the coils for nullifying their effect so that the switch-contacts open.

6. The combination in the circuit-closing switch of a surface-contact railway, of an electromagnet and contacts closed thereby, with an auxiliary armature, and circuit-opening contacts controlled by the armature for cutting all the coils out of circuit.

7. In a switch for a surface-contact railway,

Y the combination of contacts closed by the ac- 1 tion of the switch and completing a circuit between the feeder and a stud in the roadmature actuated by an undue rise of current in the coils, and means controlled by the armature for short-circuiting the series coil and t for open-circuiting the shunt-coil.

8. A combined switch and circuit-breaker for a surface-contact-railway system, comprising an iron box containing coils, contacts closed by the coils for completing the circuit from the feeder to a stud in the roadway, an armature within the magnetic attraction of both coils and actuated by undue current therein, and contacts controlled by the armature for nullifying the effect of both coils.

9. In a combined switch and circuit-breaker, for a surface-contact railway, the combination of an iron box containing a shunt-coil and a series coil with a moving part controlled by the magnetic effect of the coils and closing contacts completing a circuit from the feeder to a stud in the roadway, of an arma ture, contacts carried by the armature for short-circuiting the series coil, and a device controlled by the armature for opening the circuit of the shunt-coil.

10. The combination with the iron box of a combined switch and circuit-breaker, of the armature and coils and the lug 1 upon the box for shortening the magnetic circuit.

11. In a surface-contact-railway system, the combination, with the feeder and the sectional working conductor, of the combined switch and circuit-breaker, and a grounded contact carried by the car registering with the working conductor; whereby when any switch sticks, leaving the working conductor alive, said working conductor is short-circuited to ground and actuates the circuitbreaker.

12. The combination with an electric switch, normally tending to remain open, of a coil for closing the switch and holding it closed against such tendency, a coil in series with the switch-contacts, and means whereby, when a current which exceeds a predetermined maximum flows through the switch, said series coil causes itself and the switchenergizing coil to be cut out of circuit.

13. An electric switch, normally tending to remain open, in combination with a coil for closing the switch and holding it closed against such tendency, and a switch actuated by said coil, to open the circuit of the latter upon the flow therethrough of a currentin excess of a predetermined permissible maximum current.

14. The combination with an electric switch, normally tending to remain open, of a coil for closing the switch and holding it closed against such tendency, and a coil in series with the switch-contacts, which, upon the passage of an excessive current therethrongh, causes the switch to open.

15. The combination with an electric switch; of a coil in series with the switch-contacts for holding the switch closed, and an auxiliary switch which upon the passage of a selected excessive current through the switch and coil cuts the coils out of circuit.

16. The combination with an electric switch; of a coil for controlling said switch, and a coil in series with the switch-contacts, which controls the switch, and which, when a current which exceeds a predetermined maximum flows through the switch, open-circuits the magnet-coil and short-circuits itself.

17. The combination with an electromagnetic switch; of a coil in series with the switchcontacts, a switch in the circuit of the switchmagnet coil, and an auxiliary magnetic portion moved by the series coil to open the switch in the magnet-coil circuit.

18. The combination with an electric switch, of a magnet-coil for controlling said switch, an auxiliary coil in series with the switchcontact-s, which also controls the switch, a switch in the circuit of the magnet-coil, and an auxiliary adjustable magnetic portion which is moved by the series coil to open the switchin the magnet-coil circuit, and to shortcircuit the series coil itself.

19. In an electric-railway system, the combination with the feeder,ofa sectional conductor, normally open electromagnetic switches, each adapted to connect a conductor-section with the feeder; and a collector carried by the car, which closes the circuit of said switches, and switches which are actuated by the flow of a current which exceeds a predetermined maximum, to cut the magnet-coils out of circuit.

20. In an electric-railway system, the combination with the feeder, of a sectional conductor, normally open electromagnetic switches, each of which is adapted to connect a conductor-section with the feeder, a collector carried by the car, which closes the circuit of said switches, and switches which cut the coils of said switches out of circuit when a current exceeding a predetermined maximum flows through the switch.

21. In an electric-railwaysystem, the combination with the feeder, of a sectional working conductor; electromagnetic switches, each of which connects a conductor-section with the feeder; a sectional switch-energizing conductor, each section of which is connected with the coil of one of said switches; and a coil in series with the switch-contacts, which, when a current which exceeds a predetermined maximum flows therethrough, causes the switch to open.

22. In an electric-railway system, the combination with the feeder, of a sectional working conductor, electromagnetic switches, each of which connects a conductor-section with the feeder; a sectional switch-energizing conductor, each section of which is connected with the energizing-coil of one of saidswitches; a switch in the circuit of each of said coils; and coils, one of which is in series with the contacts of each of the feeder-switches, which coil, when a current which exceeds a predetermined maximum flows therethrough, opens the switch in the circuit of said energizingcoil.

23. In an electric-railway system, the combination with the feeder, of a sectional working conductor, switches each of which connects a conductor-section with the feeder, a sectional switch-energizing conductor; a plurality of energizing-coils, each of which is connected with a section of said energizingconductor, and actuates one of said switches; a plurality of coils, each of which controls one of said switches, and is connected in series between a section of working conductor and the feeder, which coil, when a current which exceeds a predetermined maximum flows therethrough, opens the circuit in the energizingcoil and short-circuits itself.

24. In an electric railway, the combination with a feeder, of a sectional working conductor, a sectional energizing-conductor; electromagnetic switches, each of which connects a conductor-section with the feeder, and has its coil connected between the section of energizing-conductor and ground; and means whereby each switch is opened by a current flow therethrough which exceeds a predetermined maximum.

25. In an electric-railway system, the combination with the feeder, of a working conductor, a collector carried by a car, and a normally open switch for connecting said conductor with the feeder, a magnetcoil for closing the switch and a switch actuated by a flow of current through said coil which ex ceeds a predetermined maximum, to opencircuit the coil, and permit the normally open switch to open.

26. In an electric-railway system, the combination with the feeder, of a sectional conductor; electromagnetic switches, each of which connects a conductor-section with the feeder, switches which are actuated to cut the magnet-coils out of circuit by a current flow through the switch which exceeds a predetermined maximum; and a grounded collector carried by the car which engages with a conductor-section to cause such excessive current to flow through the switch with which the conductor-section is connected.

27. In an electric-railway system, the combination with the feeder, of a sectional working conductor; electromagnetic switches, each of which connects a conductor-section with the feeder; energizing-coils for said switches, a plurality of coils, each of which is connected between a section of working conductor and the feeder, and when a current which exceeds a predetermined maximum flows therethrough, causes the switch to open; and a grounded collector carried by the car which engages with a section of working conductor to cause such excessive current to flow through the coil with which the conductorsection is connected.

28. In an electric-railway system, the combination with the feeder, of a sectional working conductor; electromagnetic switches, each of which connects a conductorsection with the feeder; a switch which is actuated by the flow of a current which exceeds a predetermined maximum through a switch to render its coil inoperative; and a grounded collector carried by the car which engages a conductor-section to cause such excessive current to flow through the switch with which that conductor-section is connected.

29. In an electric-railway system, the combination with the feeder, of a sectional working conductor; electromagnetic switches, each of which connects a conductor-section with the feeder; a switch which is actuated by the flow of a current which exceeds a predetermined maximum through the switch to cause the switch to open; and a grounded collector carried by the car which engages a conductor-section to cause such excessive current to flow through the switch with which that conductor-section is connected.

30. In an electric-railway system, the combination with the feeder, of a sectional working conductor; electromagnetic switches, each of which connects a conductor-section with the feeder; energizing-coils for said switches, a plurality of coils, each of which is connected in series between a section of working conductor and the feeder, which coil, when a current which exceeds a predetermined maximum flows therethrough, opens the circuit of the coil of one of the electromagnetic switches; and a grounded collector carried by the car which engages with a working conductor-section, to cause such excessive current to flow through the series coil which is connected with said section.

31. In an electric-railway system, the combination with the feeder, of asectional working conductor; electromagnetic switches, each of which connects a conductor-section with the feeder magnet-coils for said switches, a series coil between each section of working conductor and the feeder, which coil also controls the electromagnetic switch, and when a current which exceeds apredetermined maximum flows therethrough, opens the switchcoil circuit and also short-circuits itself; and a grounded collector carried by the car, which engages with a section of working conductor to cause such excessive current to flow through the coil with which that section is connected.

32. In an electric-railway system, the combination with the feeder, of a sectional working conductor, a sectional switch-energizing conductor; electromagnetic switches, each of which connects a working-conductor section with the feeder, and has its coil connected between a section of the switch-energizing conductor and ground, each of said switches being adapted to be opened by the flow therethrough of a current which exceeds a predetermined maximum; and a grounded collector carried by the car for engaging the working conductor-sections to cause such excessive current to flow through the switches with which the sections are connected.

33. In an electric-railway system, the com bination with the feeder, of a working con ductor, a switch for connecting said conductor with the feeder, an electromagnet for actuating said switch, a switch which is actuated by the flow through the first switch of a current exceeding a predetermined maximum to cut the coil out of circuit; and a grounded collector carried by the car which engages with the working conductor to cause such excessive flow of current through the switch.

34:. In an electric-railway system, the combination with the feeder, of a Working conductor, a switch for connecting said conductor with the feeder, an electromagnet for actuating said switch, a switch which is actuated, by the flow through the first switch of a current which exceeds a predetermined maximum, to cut the coil out of circuit; and means for causing an excessive flow through said switch when the switch fails to open.

85. In an electric-railway system, the combination with the feeder, of a sectional working conductor, electromagnetic switches conneeting the conductor sections with the feeder; a sectional switch energizing eonductor connected with the coils of said switches; switches which are actuated by the flow through the electromagnetic switches of a current which exceeds a predetermined maximum; to cut the magnet-coils out of circuit and means for causing such excessive flow when the switches are held closed by leakage currents to the energizing-conductor.

36. The combination with an electric switch, of a magnet-coil for controlling the switch, and an auxiliary switch actuated by an excessive flow of current through the controlling-coil itself, to cut the latter out of circuit.

37. In an electric railway, the combination with the feeder, of conductor-sections, electromagnetic feeder-switches for connecting said sections with the feeder, switches actuated by an excessive current flowing through the switch-magnet coils to cut the latter out of circuit, so that the feeder-switches open, and means carried by a car for causing such excessive current flow.

In witness whereof I have hereunto set my hand this 14th day of February, 1899.

. THOMAS J. JOHNSTON.

\Vitnesses:

B. B. HULL, M. E. J AOOBSON. 

